The present invention relates to a device for activating a mobile car stabilizer, designed to move from an idle position wherein it is housed inside a compartment in the car bodywork, to an operating position wherein it is located outside the contour of the bodywork and exposed to the air stream flowing over the bodywork. Known devices for moving a stabilizer from the first to the second position comprise a train of articulated members, a first of which is powered by a motor, and the last of which is connected to the stabilizer in such a manner as to move the same, via a fairly complex movement, from the said first to the said second position. Known devices of the aforementioned type present a number of drawbacks. First and foremost, in addition to being fairly complex in design and cumbersome in size, the compartment (in which the stabilizer is housed in the idle position) usually remains open and is therefore exposed to external agents when the stabilizer is moved into the operating position.